THE PLANT CELL, Vol 4, Issue 1 99-110, Copyright © 1992 by American Society of Plant Biologists
Patterns of Soybean Proline-Rich Protein Gene Expression
R. E. Wyatt, R. T. Nagao and J. L. Key
Department of Botany, University of Georgia, Athens, Georgia 30602
The expression patterns of three members of a gene family that encodes
proline-rich proteins in soybean (SbPRPs) were examined using in situ
hybridization experiments. In most instances, the expression of SbPRP genes
was intense in a limited number of cell types of a particular organ. SbPRP1
RNA was localized in several cell types of soybean hypocotyls, including
cells within the phloem and xylem. SbPRP1 expression increased within
epidermal cells in the elongating and mature regions of the hypocotyl;
expression was detected also in lignified cells surrounding the hilum of
mature seeds. SbPRP2 RNA was present in cortical cells and in the vascular
tissue of the hypocotyl, especially cells of the phloem. This gene was
expressed also in the inner integuments of the mature seed coat. SbPRP3 RNA
was localized specifically to the endodermoid layer of cells surrounding
the stele in the elongating region of the hypocotyl, as well as in the
epidermal cells of leaves and cotyledons. These data show that members of
this gene family exhibit cell-specific expression. The members of the SbPRP
gene family are expressed in different types of cells and in some cell
types that also express the glycine-rich protein or hydroxyproline-rich
glycoprotein classes of genes.
